1. Field of the Invention
The present invention relates to an optical coupling system for coupling a first optical waveguide, which has a first core surrounded by a first sheath, to a second optical waveguide which has a second core surrounded by a second sheath, where in the region of the coupling location, over at least part of a predetermined axial portion, both the second sheath and the first sheath together form a cladding of the optical waveguide, and where the first optical waveguide is preferably a polymer optical waveguide formed on a printed circuit board.
2. Description of Related Art
Printed circuit boards with integrated optical signal connections represent the next generation of signal connection on board level. The so-called optoelectronic printed circuit board is designed to allow the realization of highly complex applications which require further miniaturization as well as an increase in the integration density of product features and consequently make it possible to achieve a higher product added value of the printed circuit board. Printed circuit boards with optical connections will be used where applications require extremely high data flows between components, modules or functional units (e.g. high-end computer applications), resistance to interference from electromagnetic fields (e.g. automotive and aeronautic applications) or a space-saving design of the connection lengths (e.g. mobile applications), or where a saving in energy in comparison with resistive copper conductor traces is desired.
Optical data transmission in the long-distance range has already been known for several decades. For example, optical fibers or optical waveguides (OWG/LWL) have already been used for data transfer in continental, metropolitan and “local area” networks for many years. The use of optical waveguides in order to connect together printed circuit boards, or even to realize integrated optical connections within a printed circuit board, is thus the next step. Glass or polymer fibers are used as optical waveguides, as are planar polymer waveguides, into which research is still being conducted. Although planar polymer waveguides are inferior to glass fibers in terms of optical attenuation, which is acceptable over short distances, for example where used on printed circuit boards, these have enormous advantages in terms of processability and manufacturability, miniaturization, design freedom, and cost.
The biggest challenge in the realization of integrated optical connections on the printed circuit board by means of optical waveguides (planar waveguide technology) is the connection of the waveguide ends to optoelectronic components or to optical connector modules which create the connection to the “outside world,” for example to external glass fiber cables.